Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for San Marcos can be used to determine when you can plant black radish.

Planting Calendar for Black radish

Frost tolerance for black radish:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Black radish are one of those plants that can tolerate a little bit of cold weather which tells us that you can plant them earlier than other frost tender plants.

The earliest that you can plant black radish in San Marcos is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant black radish and expect a good harvest is probably September. If you wait any later than that and your black radish may not have a chance to really do well. Starting your black radish indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In San Marcos the average date of last frost happens on March 15. You can expect an average low temperature of 15°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for San Marcos and it can change quite a bit from year to year. Since half of the time in San Marcos it frosts late in the year after March 15 be ready to cover your black radish in the event of one of those late frosts.

USDA Zone Info for San Marcos

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in San Marcos

You may be interested in your other planting guides for San Marcos.